乳山地震序列区域台网及台阵定位结果对比

精确定位的活动图像为了解断层产状和深部构造提供了重要基础信息。本文采用2014年5月7日至2015年12月31日期间山东地震台网及乳山台阵记录的乳山地震序列M_L ≥ 1.5级地震进行双差定位对比研究。定位结果显示:山东地震台网记录的地震经精定位后,震源位置呈现北西向（约315°）展布,剖面上地震分布较为均匀,震源深度3-11km。乳山台阵记录的地震经精定位后,震源位置呈现北西西向（约290°）展布,在空间上多处相对集中,体现了序列空间分布的丛集特征;剖面中心位置地震明显较少,此处似乎存在一凹凸体,序列地震基本发生在凹凸体的周围,震源深度集中分布在4-8km。从已有震源机制解、台站布局、精定位残差、现场调查等多方面综合分析认为,乳山台阵精定位结果更加准确。

Comparision of Location of Rushan Seismic Sequence between Region Network and Array Network

Double difference algorithm is used for Rushan swarm, selecting the M_L ≥ 1.5 earthquake catalogue recorded by Shandong Seismic Network and Rushan Array from May 7, 2014 to December 31, 2015. The results show that the hypocenter location is in NW(about 315°)direction according to the accurate location of network records. The distribution of earthquakes in the section is basically uniform and the focal depth is in the range of 3-11km. Moreover, based on the accurate location of array records, the hypocenter location is in NWW(about 290°)direction. In the section, the earthquake has obvious spatial cluster characteristics, which reflects the heterogeneity of the fault plane, and the focal depth is concentrated in 4-8km. Based on the comprehensive analysis of the focal mechanism solution, the station layout, the location error and the field investigation, it is found that the accuracy of the positioning from the Rushan Array is relative higher.